True or False
A physical change is means change to matter without making it into a new kind of matter
True
Explain one kind of phase change.
In experience one, when we folded the clay matter was not conserved.
False, matter is conserved in a physical change.
We can see atoms with our own eyes.
False, atoms are too tiny to see and we need tools to see them.
Conserve means to change the total amount of something.
False
Provide an example of chemical change.
Example: a metal nail that is rusting, substances combining and making a new substance like gas
What chemical change occurred during experience two?
The baking soda and vinegar combined to create a gas to fill up the balloon.
Can mixtures have parts that settle over time?
Yes, mixtures can have parts that settle over time, like when sand sinks to the bottom of water.
Chemical reaction means a chemical change in which two or more substances mix or a single substance breaks down
True
Why can physical changes usually be reversed?
Physical changes can usually be reversed because the substance’s molecules stay the same and only its shape or state changes. No new substances are made, so it can go back to how it was before.
In experience three, how can you tell the salt is still present in the water?
You can tell because salt was still present.
What is evaporation? Is it a physical or chemical change?
Evaporation is when a liquid turns into a gas; it is a physical change.
Heat can not cause a chemical reaction.
False
What happens to matter during a chemical change?
During a chemical change, matter changes into something new. The tiny parts inside it called atoms move around and make new things.
What is an example of a heterogeneous mixture?
An example of a heterogeneous mixture is a salad because you can see and pick out the different parts like lettuce, tomatoes, and cucumbers.
What is a homogeneous mixture?
A homogeneous mixture is a mixture where the different parts are mixed so well that they look the same throughout. You cannot easily see the separate substances. Examples include salt water and air.
Burning wood is an example of a chemical reaction.
True because it changes the wood into new substances like ash, smoke, and gases.
Are mixture and substance the same thing?
No because Substance = pure and uniform composition and Mixture = combination of substances physically mixed, not chemically bonded
Why is it important to make all measurements in the same units? Explain.
Making all measurements in the same units ensures accurate calculations and comparisons. It prevents errors that happen when mixing different units.
What does GCHOP stand for?
Gas, color, heat, odor, precipitate